This section provides background information related to the present disclosure which is not necessarily prior art.
The distribution and circulation of air within a grain bin storage device has an important effect on the ecosystem of a stored material. Drying is known as an essential method of preserving food and feedstock. Proper aeration of grain and other feed assists in the drying process while maintaining desired internal moisture levels of the grain or feed. Thus, various structures, such as grain bins and other feed storage units, may use ventilation systems in an attempt to maintain a selected environment. The ventilation systems can help ensure that a supply of fresh air and acceptable levels of various properties, such as moisture content, are maintained within the structure. The ventilation systems are generally used to move volumes of air and may include various fan units to move the air.
Bin ventilation systems are often sized for a bin or storage unit that is completely full. It is often preferred, however, that bin aeration levels (cfm/bushel) be held constant regardless of the quantity, or bin fill level. Thus, a fan running at a constant speed will likely not be able to maintain the preferred aeration level at various different fill levels without user intervention. By way of example, a typical large farm bin may use two 40 hp fans that run constantly after the drying process starts, regardless of the bin fill level. However, the actual required power may only be a few horsepower until the bin is filled with grain or feed. If the amount of air supply is too large, the grain or feed may be cooled too rapidly, negatively affecting the overall amount of moisture to be removed while using excess energy. Thus, when multiple fans are used, some fans may need to be turned off periodically, or run for only a specified period of time. This may cause undesired periods of no air flow. Accordingly, there remains a need for minimizing the energy used in the drying and cooling process, while maintaining consistent air flow adequate for the proper moisture content.